Referring to FIG. 1, prior art image sensors 10 include a plurality of electrodes 15 stacked vertically beside a photosensitive area 20, and a transparent dielectric 30 is disposed over the photosensitive area 20 and between the electrodes. A microlens 40 rests on a transparent spacer 50 over the dielectric for focusing the incident light (depicted by the arrows) onto the photosensitive area 20. The majority of the incident light passes through the microlens 40 and overlaying dielectric 30 and onto the photosensitive area 20. Upon passing through the microlens 40 and subsequently, a portion of the light, however, is dispersed outwardly. As a consequent, this dispersed light does not reach the photosensitive area 20.
Although the currently known and utilized image sensors and method for making such image sensors are satisfactory, they include drawbacks. As mentioned above, a portion of the light passes between the electrodes and is not directed toward the photosensitive area 20, and as a result, there is an inherent inefficiency resulting from this mis-directed light.
Consequently, a need exists for an image sensor and a method for making such image sensors in which this inefficiency is eliminated